Faculty of Biotechnology and Food Sciences in Nitra Journal of Microbiology, Biotechnology and Food Sciences 1338-5178 vol. 5 2016 2016-04-01 2016-04-01 EFFECT OF ULTRASOUND AND THERMAL TREATMENT ON PECTIN METHYLESTERASE ACTIVITY IN PAPAYA (Carica papaya) JUICE 487 490 EN Villanueva-Tiburcio Villanueva-Tiburcio J.E. J.E. Vargas-Solórzano Vargas-Solórzano J.W. J.W. González-Reynoso González-Reynoso O. O. Leandro-Laguna Leandro-Laguna C. C. Alfaro-Cruz Alfaro-Cruz S.C. S.C. Among the pectic enzymes present in fruits and vegetables, pectin methylesterase (PME) is usually related to the loss of quality and it causes adverse effects on finished products. In this research, the kinetic of ultrasound and thermal treatments are evaluated in the PME activity in papaya juice. The results showed that the ultrasound treatment caused an increase in the catalytic activity up to 52%. After a while, the catalytic activity decreased in 27% indicating that the ultrasound was not effective in the enzymatic inactivation, whereas the thermal treatment inactivated 71% of the PME. However, these results open perspectives to evaluate the effect of ultrasound and enhance the catalytic activity of enzymes of industrial interest.